Can I update charts based on files I uploaded from my computer?

Yes, Datasets created from files that were manually uploaded from your computer and their charts can be updated using the Manual Update feature of DataHero Live Charts. This article shows how to do that.

The only thing you can't do with data that was uploaded manually is to use Scheduled Updates, which require the data to be in an online service. However, you can use Scheduled Updates with Excel spreadsheets and other files by uploading your file to a cloud storage service, such as Dropbox, Box, or Google Drive, and importing it from there.